[+] ServerResources

Author: clansty

AquaMai.Mods/Enhancement/ServerResources.cs

@@ -0,0 +1,198 @@
+using System;
+using System.Collections;
+using System.Diagnostics;
+using System.IO;
+using System.IO.Compression;
+using System.Linq;
+using System.Reflection;
+using System.Security.Cryptography;
+using AquaMai.Config.Attributes;
+using AquaMai.Core.Helpers;
+using AquaMai.Mods.Types;
+using HarmonyLib;
+using MelonLoader;
+using MelonLoader.TinyJSON;
+using Monitor;
+using Process;
+using UnityEngine;
+using UnityEngine.Networking;
+
+namespace AquaMai.Mods.Enhancement;
+
+[ConfigSection(
+    defaultOn: true,
+    exampleHidden: true,
+    zh: "加载服务器下发的资源（如果支持）")]
+public class ServerResources
+{
+    [ConfigEntry]
+    private static readonly string publicKey =
+        "zJo+1YAJXHorMNSs0abC/qQchDX9J7um07mUp+jkYUVh9Y74IUKeSLlSoMrhardJJolQMcy+m7qtdx/xyTmp8pyANBi7xxgUB752SRhHBnK4XQhALd0WmTo4hE6deRHl/SlDxbfZM+c0fW4FMrHUFpHCy+JQoTvJPXkLQRfOCik=";
+
+    [ConfigEntry]
+    private static readonly string cacheFile = "LocalAssets/ServerResources";
+
+    private const string FieldName = "_aquaMaiResources";
+
+    private class ServerResourcesEntry : ConditionalMessage
+    {
+        public string url;
+        public string sign;
+    }
+
+    private class ServerResourcesData
+    {
+        public ServerResourcesEntry[] entries = [];
+    }
+
+    private static ServerResourcesEntry _entry;
+    public static AssetBundle bundle;
+    private static Download0rder _downloader;
+
+    public static void OnBeforePatch()
+    {
+        NetPacketHook.OnNetPacketComplete += OnNetPacketComplete;
+    }
+
+    private static Variant OnNetPacketComplete(string api, Variant _, Variant response)
+    {
+        if (bundle != null) return null;
+        if (_downloader != null) return null;
+        if (_entry != null) return null;
+        if (api != "GetGameSettingApi" || response is not ProxyObject obj) return null;
+        var serverResourcesJson = obj.Keys.Contains(FieldName) ? obj[FieldName] : null;
+        if (serverResourcesJson == null) return null;
+
+        var data = serverResourcesJson.Make<ServerResourcesData>();
+        _entry = data.entries.FirstOrDefault(it => it.ShouldShow());
+        if (_entry == null) return null;
+        if (File.Exists(cacheFile))
+        {
+            var cached = File.ReadAllBytes(cacheFile);
+            if (VerifySignature(cached, _entry.sign)
+#if DEBUG
+                || File.Exists("LocalAssets/ServerResourcesDebug")
+#endif
+            )
+            {
+                LoadFile();
+                return null;
+            }
+#if DEBUG
+            MelonLogger.Msg("[ServerResources] Invalid signature for existed file");
+#endif
+            File.Delete(cacheFile);
+        }
+
+        blinktimer.Start();
+        var go = new GameObject("[AquaMai] ServerResourcesDownloader");
+        _downloader = go.AddComponent<Download0rder>();
+
+        return null;
+    }
+
+    private class Download0rder : MonoBehaviour
+    {
+        private void Start()
+        {
+            StartCoroutine(GetFile());
+        }
+
+        private IEnumerator GetFile()
+        {
+            yield return GetFileImpl();
+            Destroy(this);
+        }
+    }
+
+    private static byte _poweronState = 0;
+    private static Stopwatch blinktimer = new Stopwatch();
+    [HarmonyPrefix]
+    [HarmonyPatch(typeof(PowerOnMonitor), nameof(PowerOnMonitor.SetMainMessage))]
+    public static void PreSetMainMessage(ref string mmessage, ref string smessage)
+    {
+        if (_poweronState < 4) return;
+        if (_downloader == null) return;
+        mmessage += "\n\nSERVER RESOURCES";
+        if (_poweronState == 255)
+        {
+            smessage += Util.Utility.isBlinkDisp(blinktimer) ? "\n\nLOADING" : string.Empty;
+        }
+    }
+
+    [HarmonyPrefix]
+    [HarmonyPatch(typeof(PowerOnProcess), "OnUpdate")]
+    public static void PrePowerOnStart(ref byte ____state)
+    {
+        if (____state == 9 && _downloader != null)
+        {
+            ____state = 255;
+        }
+        if (____state == 255 && _downloader == null)
+        {
+            ____state = 9;
+        }
+        _poweronState = ____state;
+    }
+
+    private static IEnumerator GetFileImpl()
+    {
+#if DEBUG
+        yield return new WaitForSeconds(2); // DEBUG
+#endif
+        using var webRequest = UnityWebRequest.Get(_entry.url);
+        yield return webRequest.SendWebRequest();
+
+        if (webRequest.isNetworkError)
+        {
+            MelonLogger.Warning("[ServerResources] Unable to download file: " + webRequest.error);
+            yield break;
+        }
+
+        var bytes = webRequest.downloadHandler.data;
+        if (!VerifySignature(bytes, _entry.sign))
+        {
+            MelonLogger.Warning("[ServerResources] Invalid signature for file");
+            // yield break;
+        }
+
+        File.WriteAllBytes(cacheFile, bytes);
+        LoadFile();
+    }
+
+    private static void LoadFile()
+    {
+        bundle = AssetBundle.LoadFromFile(Path.Combine(Environment.CurrentDirectory, cacheFile));
+        if (bundle == null)
+        {
+            MelonLogger.Error($"[ServerResources] Failed to load asset bundle from {Path.Combine(Environment.CurrentDirectory, cacheFile)}");
+            return;
+        }
+        var compressed = bundle.LoadAsset<TextAsset>("AquaMaiExtension");
+        if (compressed == null) return;
+        using var ms = new MemoryStream(compressed.bytes);
+        using var ds = new DeflateStream(ms, CompressionMode.Decompress);
+        using var os = new MemoryStream();
+        ds.CopyTo(os);
+        var bytes = os.ToArray();
+        var asm = AppDomain.CurrentDomain.Load(bytes);
+        var ext = asm.GetType("AquaMai.Extension.Entrypoint");
+        var main = ext.GetMethod("Main", BindingFlags.Static | BindingFlags.Public);
+        main.Invoke(null, []);
+    }
+
+    private static bool VerifySignature(byte[] data, string signatureBase64)
+    {
+        var signature = Convert.FromBase64String(signatureBase64);
+        var pubKey = Convert.FromBase64String(publicKey);
+
+        var param = new RSAParameters
+        {
+            Modulus = pubKey,
+            Exponent = [1, 0, 1],
+        };
+        using var rsa = RSA.Create();
+        rsa.ImportParameters(param);
+        return rsa.VerifyData(data, signature, HashAlgorithmName.SHA256, RSASignaturePadding.Pkcs1);
+    }
+}